Viron P. “Pete” Vaky, 87, a career diplomat who was the U.S. ambassador to three countries and was the State Department’s chief architect of Latin American policy in the late 1970s, died Nov. 22 at Collington Episcopal Life Care Community, a retirement facility in Mitchellville. He had pneumonia, his son Peter Vaky said.

Mr. Vaky (pronounced “VAY-kee”) joined the Foreign Service in 1949 and had assignments throughout South America and Central America. He became known for promoting a far-reaching vision of inter-American diplomatic relations that sometimes went against the prevailing views of other government leaders.

After serving as a key aide to national security adviser Henry Kissinger in the early 1970s, Mr. Vaky was named ambassador to Costa Rica in 1972. He later served as ambassador to Colombia (1974-76) and Venezuela (1976-78).

From 1978 to 1980, as assistant secretary of state for inter-American affairs, Mr. Vaky guided U.S. policy at a time of volatile relations with Nicaragua, El Salvador and other countries. He helped coordinate the transition of the Panama Canal from U.S. to Panamanian control and helped negotiate the release of U.S. ambassador Diego Asencio and other diplomats taken hostage in Colombia in 1980.

“He was a real giant and an extraordinary diplomat,” Michael Shifter, president of the Washington-based Inter-American Dialogue and an authority on Latin America, said in an interview. “He’s one of those characters in Washington that people should know about. He was somebody who had a commitment of principles,” with a sense of what was possible and practical.

Viron P. “Pete” Vaky, 87, a career diplomat who was the U.S. ambassador to three countries and was the State Department’s chief architect of Latin American policy in the late 1970s, died Nov. 22. (Rick Reinhard /Impact Digitals)

In 1979, Mr. Vaky attempted to persuade Nicaraguan strongman Anastasio Somoza Debayle to give up power during what became known as the Sandinista revolution. Somoza refused to yield and ended up unleashing bombs on neighborhoods suspected of harboring Sandinista sympathizers. Hundreds of civilians were killed during the crackdown, and many others were seized and tortured.

“No negotiation, mediation or compromise can be achieved any longer with a Somoza government,” Mr. Vaky said in 1979. “Too much blood, too much hate, too much polarization have occurred for this to be possible.”

Somoza was ultimately driven from the country and sought refuge in Paraguay, where he was assassinated in 1980.

Earlier in Mr. Vaky’s career, when he was deputy chief of mission in Guatemala, he wrote a sharply worded memorandum to his superiors at the State Department opposing U.S. support of counterterrorist practices of the Guatemalan government.

In 1968, when kidnapping, brutal interrogations and political assassinations of suspected Communists by state-sanctioned security forces were rampant, Mr. Vaky wrote that it was morally wrong to ignore the “violence of right-wing vigilantes and sheer criminality” of the Guatemalan regime.

“In the minds of many in Latin America,” he wrote, “we are believed to have condoned these tactics, if not actually to have encouraged them.”

Although it remained classified for 30 years, Mr. Vaky’s memorandum became known as something of a touchstone of diplomatic conscience and courage.

The “most disturbing” conclusion, in his view, was that “we have not been honest with ourselves . . . Have our values been so twisted by our adversary concept of politics in the hemisphere? Is it conceivable that we are so obsessed with insurgency that we are prepared to rationalize murder as an acceptable counter-insurgency weapon?”

In 1999, one year after Mr. Vaky’s memorandum was declassified, President Bill Clinton visited Guatemala and apologized for U.S. support of the country’s repressive regimes in the past.

Viron Peter Vaky was born Sept. 13, 1925, in Corpus Christi, Tex., to Greek immigrant parents. His first name, which he pronounced “VEER-un,” was based on the name of Lord Byron, the British poet who had fought for Greek independence from Turkey in the 19th century.

Mr. Vaky served in the Army Signal Corps during World War II and was a 1947 graduate of Georgetown University’s School of Foreign Service. He received a master’s degree in international relations from the University of Chicago in 1948.

Survivors include his wife of 63 years, Luann Colburn Vaky of Mitchellville; three sons, Peter Vaky of Atlanta, Paul Vaky of Bogota, Colombia, and Matthew Vaky of Gaithersburg; and 10 grandchildren.

After retiring from the Foreign Service in 1980, Mr. Vaky taught at Georgetown, where he was an associate dean of the School of Foreign Service. He was also associated with the Carnegie Endowment for International Peace and the Inter-American Dialogue, a Washington-based think tank that studies policies affecting countries in the Western Hemisphere.

Mr. Vaky often wrote articles about Latin American diplomacy, but the impassioned tone of his long-classified 1968 State Department memo still carries a powerful message.

“If the U.S. cannot come up with any better suggestion on how to fight insurgency in Guatemala than to condone counter-terror,” Mr Vaky wrote, “we are in a bad way indeed.”

Matt Schudel has been an obituary writer at The Washington Post since 2004.